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 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
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 * or LICENSE.txt.  See the License for the specific
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 * file and include the License file at LICENSE.txt.
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package org.glassfish.grizzly.http2;

import org.glassfish.grizzly.Buffer;
import org.glassfish.grizzly.http2.frames.HeaderBlockHead;
import org.glassfish.grizzly.http2.hpack.Decoder;
import org.glassfish.grizzly.http2.hpack.DecodingCallback;
import org.glassfish.grizzly.memory.Buffers;
import org.glassfish.grizzly.memory.MemoryManager;

/**
 *
 * @author oleksiys
 */
public class HeadersDecoder {
    private final Decoder hpackDecoder;
    private final MemoryManager memoryManager;
    private final int maxHeaderSize;
    private int currentHeaderSize;

    private HeaderBlockHead firstHeaderFrame;
    private Buffer inBuffer;

    // @TODO Implement maxHeaderSize limitation handling
    public HeadersDecoder(final MemoryManager memoryManager,
                          final int maxHeaderSize,
                          final int maxHeaderTableSize) {
        this.memoryManager = memoryManager;
        this.maxHeaderSize = maxHeaderSize;
        this.hpackDecoder =  new Decoder(maxHeaderTableSize);
    }

    public boolean append(final Buffer buffer) {
        currentHeaderSize += buffer.remaining();
        if (currentHeaderSize <= maxHeaderSize) {
            inBuffer = Buffers.appendBuffers(memoryManager, inBuffer, buffer, true);
            return true;
        }
        return false;
    }
    
    public void decode(final DecodingCallback callback) {
        if (inBuffer != null) {
            hpackDecoder.decode(inBuffer, !isProcessingHeaders(), callback);
            
            inBuffer.tryDispose();
            inBuffer = null;
        }
    }

    public HeaderBlockHead finishHeader() {
        final HeaderBlockHead firstHeaderFrameLocal = firstHeaderFrame;
        firstHeaderFrame = null;
        currentHeaderSize = 0;
        return firstHeaderFrameLocal;
    }

    public void setFirstHeaderFrame(
            final HeaderBlockHead firstHeaderFrame) {
        this.firstHeaderFrame = firstHeaderFrame;
    }

    public boolean isProcessingHeaders() {
        return firstHeaderFrame != null;
    }
}
